Data buffers having allocatable data storage segments have been employed for enhancing the data transfer characteristics of a peripheral data storage system, including those employing magnetic tape recorders. The documents incorporated by reference illustrate such a system. U.S. Pat. No. 4,403,286 indicates that total peripheral system performance can be enhanced by adjusting the peripheral system operation for balancing the workloads between various data buffers in the peripheral system. The performance, i.e., short access time, of the peripheral data storage system can be further enhanced by managing the operation of the data buffer in diverse ways.
For example, the Casey, et al article "Replacement Algorithms for Storage Management in Relational Data Bases" IEEE COMPUTER JOURNAL, Nov. 1976, pp. 306-314 teaches that relations in a data base are variably sized. Each defined relation can have a plurality of allocatable memory units or segments. Each relation has but one entry in a replacement control, which includes a least-recently used (LRU) linked list. This reference shows grouping allocatable segments as a single unit on an LRU linked list.
The U.S. Pat. No. 4,099,235, Hoschler, shows a telephone switching system having a plurality of control computers, which balance their loading based upon a "current measured utilization ratio". This ratio is a quotient of call waiting time divided by computer free or available time. Upon reaching predetermined thresholds, incoming calls are assigned to various control computers (task reassignment, or reallocation). This patent therefore teaches that workloading is a factor in determining reconfiguration, or task reassignment. U.S. Pat. No. 4,008,460 is an example of timestamping an LRU linked list for enabling early cast out, or deallocation of allocated data storage segments of a memory. U.S. Pat. No. 3,898,624 shows varying the bandwidth of a data cache by varying the prefetching time so that more or less allocation in the cache depends on operator-inputted controls.
U.S. Pat. No. 4,403,286 shows the use of counting channel command retries (CCRs) for the purpose of load balancing.